Soap Bubble
Soap Bubble - Related Videos
01:13
Excess Pressure Inside a Drop and a Bubble
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2023
The shape of a small drop of liquid can be considered spherical, neglecting the effect of gravity. This drop can further be considered as two equal hemispherical drops put together due to surface tension. The forces acting on the spherical drop are due to the pressure of the liquid inside the drop, the pressure due to air outside the drop, and the force due to the surface tension acting on the two hemispherical drops. where γ corresponds to the surface tension. Recalling that the force per...
08:19
Induction of Microstreaming by Nonspherical Bubble Oscillations in an Acoustic Levitation System
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Cited by 2 •
2021
A fast and reliable technique is proposed to control the shape oscillations of a single, trapped acoustic bubble that is based on coalescence technique between two bubbles. The steady-state, symmetry-controlled bubble shape oscillations allow analysis of the fluid flow generated in the vicinity of the bubble interface.
07:18
Lipid Bilayer Experiments with Contact Bubble Bilayers for Patch-Clampers
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Cited by 12 •
2019
Here, we present a protocol for the formation of lipid bilayers using a contact bubble bilayer method. A water bubble is blown into an organic solvent, whereby a monolayer is formed at the water-oil interface. Two pipettes are manipulated to dock the bubbles to form a bilayer.
11:08
Cultivation of Green Microalgae in Bubble Column Photobioreactors and an Assay for Neutral Lipids
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Cited by 23 •
2019
Here, we present a protocol to construct lab-scale bubble column photobioreactors and use them to culture microalgae. It also provides a method for the determination of the culture growth rate and neutral lipid content.
11:14
A Microfluidic System with Surface Patterning for Investigating Cavitation Bubble(s)–Cell Interaction and the Resultant Bioeffects at the Single-cell Level
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Cited by 8 •
2017
A microfluidic chip was fabricated to produce pairs of gold dots for tandem bubble generation and fibronectin-coated islands for single-cell patterning nearby. The resultant flow field was characterized by particle image velocimetry and was employed to study various bioeffects, including cell membrane poration, membrane deformation, and intracellular calcium response.
FAQs
Curvature determines how strongly surface tension acts on the enclosed air. Because the film has two air–liquid interfaces, their inward forces must be balanced by a pressure difference between the bubble’s interior and exterior. The resulting pressure difference varies with curvature, making bubble geometry essential for analyzing capillarity and Laplace pressure.
A bubble film has an inner boundary with the trapped air and an outer boundary with the surrounding air. Surface tension acts at both boundaries, so the inward contribution is greater than it would be for a single interface. This two-interface structure is why soap bubbles provide a useful physical example of Laplace pressure.
Surfactant molecules reduce water’s surface tension, allowing a liquid film to form and remain associated with a curved boundary. Their presence changes how the film responds to surface forces, helping the bubble persist long enough to display pressure and optical effects. This stabilization makes the system useful for studying liquid films rather than transient water surfaces alone.
Light reflected from the two sides of the thin liquid film can combine through thin-film interference. The resulting colors depend on film thickness, so changes in thickness alter which wavelengths appear most strongly. Shifting colors therefore provide a visible indication that the film is not uniform or static, connecting an optical observation to the bubble’s physical state.
Researchers can examine the bubble’s curved shape, surface forces, and interior–exterior pressure difference as a compact model of capillarity. The system links observable geometry with the behavior of a liquid interface. It also allows related ideas, including Laplace pressure and thin-film interference, to be considered together in one accessible physical example.
A bubble’s changing appearance can reveal information about the liquid film’s condition. Its shape reflects the balance between surface tension and pressure, while shifting colors indicate changes in film thickness through interference. Considering both observations together helps distinguish mechanical behavior of the curved boundary from optical effects produced within the film.
Soap bubbles serve as simplified models for systems containing thin liquid films and interfaces. The same scientific ideas examined through a bubble, including surface tension, curvature, pressure, and film-thickness effects, inform research on foams, coatings, emulsions, and other soft-matter systems. Their value lies in connecting visible behavior with broader interfacial phenomena.